Currently struggling on this, I need the most help right now

Name the most appropriate metric unit for each measurement like a length of an carrot

Giuseppi's pizza had orders for $931.00 of pizzas. the prices were $21 for a large pizza, 514 for a medium pizza, and $7 for a small pizza. the number of large pizzas was two less than four times the number of medium pizzas. thenumber of small pizzas was three more than three times the number of medium pizzas. how many of each size of pizza were ordered?

Which describes the difference between the graph of f(x)=x^2 and g(x)=-(x^2-2)